Considerable study and investigation has been undertaken with respect to coal-fired furnaces for use in generation of heat. Such furnaces are presenting major environmental concerns in most industrialized areas. In the combustion of coal, many combustion products which emerge from the stack of the system can cause, or have the potential to cause environmental damage. One of the problems of particular concern is soot emissions from the stacks of coal-fired furnaces. This is due primarily to incomplete combustion of the coal in the furnace. Steps have been taken to remove the soot from the emissions; however, there becomes an economic balance with respect to how much of the soot can be removed versus the costs in doing same. To reduce the pressures on soot removal systems, it would be advantageous to improve combustion in the coal-fire furnaces. Many steps have been taken in this regard with respect to controlling the particle size of the pulverized coal which is fed to the fireball of the furnace. Furthermore, the supply of air is adjusted to provide as complete as possible combustion within the furnace. It has even been contemplated to add various catalysts and the like to the pulverized coal to enhance combustion in the fireball.
Soot control has also been studied with respect to the combustion of fuel oils in oil-fired furnaces. For example, U.S. Pat. Nos. 2,818,416; 2,898,359; 3,122,577; 3,217,022; 3,341,311; 3,535,356 and 3,989,731, disclose that an iron-containing compound ferrocene has been used to improve combustion of the fuel oils and gasolines. It is also known to use ferrocene as an additive to improve combustion of solid propellants, such as rocket fuels. Use of ferrocene in this regard is disclosed in U.S. Pat. Nos. 2,694,721; 3,564,034; 3,577,449; 3,739,004; 3,813,307; 3,816,380; 3,878,233 and 4,108,696.